"Nodal gap" induced by the incommensurate diagonal spin density modulation in underdoped high-$T_c$ superconductors

TL;DR

This paper proposes that incommensurate diagonal spin-density-wave order explains the full gapping of the Fermi surface in underdoped high-$T_c$ superconductors, challenging traditional $d$-wave pairing theories.

Contribution

It introduces a novel explanation for the nodal gap phenomenon using incommensurate spin-density-wave order, aligning well with experimental observations.

Findings

Fermi surface is fully gapped in underdoped cuprates.

Incommensurate diagonal SDW order accounts for the nodal gap.

Results agree with key experimental data.

Abstract

Recently it was revealed that the whole Fermi surface is fully gapped for several families of underdoped cuprates. The existence of the finite energy gap along the $d$-wave nodal lines ("nodal gap") contrasts the common understanding of the $d$-wave pairing symmetry, which challenges the present theories for the high-$T_c$ superconductors. Here we propose that the incommensurate diagonal spin-density-wave order can account for the above experimental observation. The Fermi surface and the local density of states are also studied. Our results are in good agreement with many important experiments in high-$T_c$ superconductors.